We present our observations toward Sgr B2 region in J = 1-0 lines of (CO)-C-12, (CO)-C-13, (CO)-O-18 and (CO)-O-17 using 13.7-m Delingha millimeter telescope with newly installed 9-beam SIS superconducting receiver. From the integrated line intensity, we derive the abundance ratio of (CO)-O-18/(CO)-O-17 with a mean value of 3.11 +/- 0.10, which is consistent with the previous results.